Hello,
First off, thanks again for providing gluster. Awesome project.
This is a n00bish question. I thought that gluster goes through the VFS
like any other filesystem, which is where the most of the filesystem
caching takes place. (Somewhat Simplified)
I'm seeing a major difference in benchmarks when comparing small-ish
files locally versus on gluster. Namely, about 40x different on writes.
I don't really think this is a problem, but am just seeking a greater
understanding. Server / client are all on 3.0.3. Servers are two
machines in a replicate setup.
Client: CentOS 5.4 2.6.18-164.15.1.el5.centos
Servers: F12 2.6.32.9-70.fc12.x86_64
-----------------------------------------
(To Gluster)
[root at linuxdb1 tiobench-gluster.2]# tiotest -b 16384 -r 4096 -f 32 -t 16
-d .
Tiotest results for 16 concurrent io threads:
,----------------------------------------------------------------------.
| Item | Time | Rate | Usr CPU | Sys CPU |
+-----------------------+----------+--------------+----------+---------+
| Write 512 MBs | 16.7 s | 30.731 MB/s | 2.0 % | 33.5 % |
| Random Write 1024 MBs | 38.9 s | 26.314 MB/s | 1.8 % | 32.5 % |
| Read 512 MBs | 4.8 s | 107.145 MB/s | 4.0 % | 221.4 % |
| Random Read 1024 MBs | 4.2 s | 241.220 MB/s | 11.6 % | 543.4 % |
`----------------------------------------------------------------------'
Tiotest latency results:
,-------------------------------------------------------------------------.
| Item | Average latency | Maximum latency | % >2 sec | % >10 sec |
+--------------+-----------------+-----------------+----------+-----------+
| Write | 7.747 ms | 240.730 ms | 0.00000 | 0.00000 |
| Random Write | 8.709 ms | 2425.524 ms | 0.00153 | 0.00000 |
| Read | 2.009 ms | 1575.232 ms | 0.00000 | 0.00000 |
| Random Read | 0.930 ms | 236.096 ms | 0.00000 | 0.00000 |
|--------------+-----------------+-----------------+----------+-----------|
| Total | 4.839 ms | 2425.524 ms | 0.00051 | 0.00000 |
`--------------+-----------------+-----------------+----------+-----------'
(To Local)
[root at linuxdb1 tiobench-gluster.2]# tiotest -b 16384 -r 4096 -f 32 -t 16
-d ~
Tiotest results for 16 concurrent io threads:
,----------------------------------------------------------------------.
| Item | Time | Rate | Usr CPU | Sys CPU |
+-----------------------+----------+--------------+----------+---------+
| Write 512 MBs | 35.7 s | 14.361 MB/s | 0.5 % | 833.8 % |
| Random Write 1024 MBs | 100.6 s | 10.182 MB/s | 0.4 % | 379.5 % |
| Read 512 MBs | 0.1 s | 4043.978 MB/s | 74.2 % | 5832.1 % |
| Random Read 1024 MBs | 0.2 s | 4171.521 MB/s | 131.2 % | 6425.0 % |
`----------------------------------------------------------------------'
Tiotest latency results:
,-------------------------------------------------------------------------.
| Item | Average latency | Maximum latency | % >2 sec | % >10 sec |
+--------------+-----------------+-----------------+----------+-----------+
| Write | 0.846 ms | 154.874 ms | 0.00000 | 0.00000 |
| Random Write | 0.185 ms | 265.350 ms | 0.00000 | 0.00000 |
| Read | 0.044 ms | 13.088 ms | 0.00000 | 0.00000 |
| Random Read | 0.043 ms | 16.019 ms | 0.00000 | 0.00000 |
|--------------+-----------------+-----------------+----------+-----------|
| Total | 0.224 ms | 265.350 ms | 0.00000 | 0.00000 |
`--------------+-----------------+-----------------+----------+-----------'
---------------------------------------
Volume Files. The machine in question is mounting the linuxdb1 volume.
Any criticisms of the way these files are setup are also extremely welcome.
[root at x2100-gfs1 glusterfs]# cat glusterfsd.vol
## file auto generated by /usr/bin/glusterfs-volgen (export.vol)
# Cmd line:
# $ /usr/bin/glusterfs-volgen --name DBMirror --raid 1
x2100-gfs1:/data/gfs/DBMirror x2100-gfs2:/data/gfs/DBMirror
############# pdb Mirror #####################################
# RAID 1
# TRANSPORT-TYPE tcp
# mounted by test environment. Currently setup as
# a replicate, or raid1, across x2100-gfs1 and x2100-gfs2
##################################################################
volume pdb-posix
type storage/posix
option directory /data/gfs/pdb
end-volume
volume pdb-locks
type features/locks
subvolumes pdb-posix
end-volume
volume pdb-iothreads
type performance/io-threads
option thread-count 8
subvolumes pdb-locks
end-volume
############# linuxdb1 Mirror #####################################
# RAID 1
# TRANSPORT-TYPE tcp
# mounted by linuxdb1 Currently configured as a
# replicate, or raid1, across x2100-gfs1 and x2100-gfs2
##################################################################
volume linuxdb1-posix
type storage/posix
option directory /data/gfs/linuxdb1
end-volume
volume linuxdb1-locks
type features/locks
subvolumes linuxdb1-posix
end-volume
volume linuxdb1-iothreads
type performance/io-threads
option thread-count 8
subvolumes linuxdb1-locks
end-volume
############# vmmirror1 Mirror ###################################
# RAID 1
# TRANSPORT-TYPE tcp
# mounted by stuff (archtest01). Currently configured as a
# replicate, or raid1, across x2100-gfs1 and x2100-gfs2
##################################################################
volume vmmirror1-posix
type storage/posix
option directory /data/gfs/vmmirror1
end-volume
volume vmmirror1-locks
type features/locks
subvolumes vmmirror1-posix
end-volume
volume vmmirror1-iothreads
type performance/io-threads
option thread-count 8
subvolumes vmmirror1-locks
end-volume
############# GLOBAL SPECIFICATIONS ###############################
# TRANSPORT-TYPE tcp
# global options. Currently configured to export volumes linuxdb1
# and pdb.
##################################################################
volume server-tcp
type protocol/server
option transport-type tcp
option auth.addr.pdb-iothreads.allow *
option auth.addr.linuxdb1-iothreads.allow *
option auth.addr.vmmirror1-iothreads.allow *
option transport.socket.listen-port 6996
option transport.socket.nodelay on
subvolumes pdb-iothreads linuxdb1-iothreads vmmirror1-iothreads
end-volume
[root at x2100-gfs1 glusterfs]# cat glusterfs.vol
## file auto generated by /usr/bin/glusterfs-volgen (mount.vol)
# Cmd line:
# $ /usr/bin/glusterfs-volgen --name DBMirror --raid 1
x2100-gfs1:/data/gfs/DBMirror x2100-gfs2:/data/gfs/DBMirror
############# PDB Mirror #####################################
# RAID 1
# TRANSPORT-TYPE tcp
# Intended for pdb test environment
# Volume-name: pdb
##############################################################
volume x2100-gfs1-pdb
type protocol/client
option transport-type tcp
option remote-host x2100-gfs1
option transport.socket.nodelay on
option remote-port 6996
option remote-subvolume pdb-iothreads
end-volume
volume x2100-gfs2-pdb
type protocol/client
option transport-type tcp
option remote-host x2100-gfs2
option transport.socket.nodelay on
option remote-port 6996
option remote-subvolume pdb-iothreads
end-volume
# Name of the volume as specified at mount time
volume pdb
type cluster/replicate
subvolumes x2100-gfs1-pdb x2100-gfs2-pdb
end-volume
volume pdb-writebehind
type performance/write-behind
option cache-size 4MB
subvolumes pdb
end-volume
volume pdb-readahead
type performance/read-ahead
option page-count 4
subvolumes pdb-writebehind
end-volume
volume pdb-iocache
type performance/io-cache
option cache-size `grep 'MemTotal' /proc/meminfo | awk '{print $2
* 0.2 / 1024}' | cut -f1 -d.`MB
option cache-timeout 1
subvolumes pdb-readahead
end-volume
volume pdb-quickread
type performance/quick-read
option cache-timeout 1
option max-file-size 64kB
subvolumes pdb-iocache
end-volume
volume pdb-statprefetch
type performance/stat-prefetch
subvolumes pdb-quickread
end-volume
############# linuxdb Mirror #####################################
# RAID 1
# TRANSPORT-TYPE tcp
# Intended for linuxdb1 to mount
# Volume-name: linuxdb1
##################################################################
volume x2100-gfs1-linuxdb1
type protocol/client
option transport-type tcp
option remote-host x2100-gfs1
option transport.socket.nodelay on
option remote-port 6996
option remote-subvolume linuxdb1-iothreads
end-volume
volume x2100-gfs2-linuxdb1
type protocol/client
option transport-type tcp
option remote-host x2100-gfs2
option transport.socket.nodelay on
option transport.remote-port 6996
option remote-subvolume linuxdb1-iothreads
end-volume
# Name of the volume as specified at mount time
volume linuxdb1
type cluster/replicate
subvolumes x2100-gfs1-linuxdb1 x2100-gfs2-linuxdb1
end-volume
volume linuxdb1-writebehind
type performance/write-behind
option cache-size 4MB
subvolumes linuxdb1
end-volume
volume linuxdb1-readahead
type performance/read-ahead
option page-count 4
subvolumes linuxdb1-writebehind
end-volume
volume linuxdb1-iocache
type performance/io-cache
option cache-size `grep 'MemTotal' /proc/meminfo | awk '{print $2
* 0.2 / 1024}' | cut -f1 -d.`MB
option cache-timeout 1
subvolumes linuxdb1-readahead
end-volume
volume linuxdb1-quickread
type performance/quick-read
option cache-timeout 1
option max-file-size 64kB
subvolumes linuxdb1-iocache
end-volume
volume linuxdb1-statprefetch
type performance/stat-prefetch
subvolumes linuxdb1-quickread
end-volume
############# Virtual Images Mirror ###############################
# RAID 1
# TRANSPORT-TYPE tcp
# Intended for vm testing servers to mount
# Volume-name: vmmirror1
##################################################################
volume x2100-gfs1-vmmirror1
type protocol/client
option transport-type tcp
option remote-host x2100-gfs1
option transport.socket.nodelay on
option remote-port 6996
option remote-subvolume vmmirror1-iothreads
end-volume
volume x2100-gfs2-vmmirror1
type protocol/client
option transport-type tcp
option remote-host x2100-gfs2
option transport.socket.nodelay on
option remote-port 6996
option remote-subvolume vmmirror1-iothreads
end-volume
# Name of the volume as specified at mount time
volume vmmirror1
type cluster/replicate
subvolumes x2100-gfs1-vmmirror1 x2100-gfs2-vmmirror1
end-volume
volume vmmirror1-writebehind
type performance/write-behind
option cache-size 4MB
subvolumes vmmirror1
end-volume
volume vmmirror1-readahead
type performance/read-ahead
option page-count 4
subvolumes vmmirror1-writebehind
end-volume
volume vmmirror1-iocache
type performance/io-cache
option cache-size `grep 'MemTotal' /proc/meminfo | awk '{print $2
* 0.2 / 1024}' | cut -f1 -d.`MB
option cache-timeout 1
subvolumes vmmirror1-readahead
end-volume
volume vmmirror1-quickread
type performance/quick-read
option cache-timeout 1
option max-file-size 64kB
subvolumes vmmirror1-iocache
end-volume
volume vmmirror1-statprefetch
type performance/stat-prefetch
subvolumes vmmirror1-quickread
end-volume
Thanks!
